Refrigerating apparatus



July 11, 1939. A. PH|L|PP 2,165,505

, REFRIGERATING APPARATUS Q Original Filed Sept. 28, 1934 w Z a w W Q L W v 5 y w J a y u v m v W Y q u m} h y W/ Zm W n 5 m INVENTOR.

Hives/me a; PHIL/PP W wuw ATTORNEY.

u .fi M u -M v hm ---MMNM$MMQNQMNNflW-ME h :H w

Patented July 11, 1939 UNITED STATES PATENT OFFICE mesne assignments, to Nash-Kelvinator Corporation, Detroit, Mich a corporation of Maryland Application September as, 1934, Serial No. 745,908

Renewed November 18, 1937 2 Claims.

My invention pertains to refrigerator cooling units and more particularly to defrosting cooling units suitable for use with two-temperature systems.

It is an object of my invention to' provide an improved two-temperature refrigerator cooling unit comprising a large finned cooling plate for cooling the food storage compartment and a freezing chamber enclosure supported from the center of the cooling plate.

It is a further object of my invention to provide an improved two-temperature refrigerator which is cyclically defrosting in operation comprising a heat insulating cabinet enclosing a food storage compartment having a large finned cooling plate supported in parallel adjacent relation to one of the walls thereof and a-freezing chamber enclosure supported in projected relation from the face of the cooling plate in conjunction with means for supplying liquefied refrigerant to said cooling plate and freezing chamber to maintain different vaporizing pressures and temperatures therein.

Another object of my invention is to provide an improved defrosting refrigerator comprising a finned cooling plate supported adjacent the upper wall of the food storage compartment.

The invention itself, however, both as to its organization and itsmethod of operation, together with additional objects and advantages thereof,.will best be understood from the following description of specific embodiments, when read in conjunction with the accompanying drawing, in which:

Fig. 1 is a front sectional view taken on line I-I of Fig. 2 showing a refrigerator constructed in accordance with my invention;

Fig. 2 is a sectional view thereof taken on line IIII of Fig. 1;

Fig. 3 is a cross sectional view taken on line I1IIII of Fig. 2; and

Fig. 4 is a sectional view showing another embodiment of my invention.

Referring more particularly to Figs. 1, 2 and 3 of the drawing I have illustrated the installation of my defrosting two-temperature cooling unit in aheat insulating refrigeration cabinet com-' prising a top wall 3, bottom wall 5, back wall .1 and side walls 9 of conventional heat insulating construction. The back wall 1 of the cabinet .terminates short of the top wall 3, and a transversely disposed horizontal heat insulating wall ll joins therewith to provide a shelf for supporting the refrigerator machine. A transverse heat insulating wall 13 extends vertically from the front edge of the machine shelf II to the top wall 3. The front opening of the cabinet is closed by a door. l3 of heat insulating construction which is hinged to swing on the front edge of the cabinet at either side of the opening.

The inner and outer surfaces of the heat insulating walls are covered with inner and outer sheet metal panels l5 and I6 respectively which may be provided with a hard smooth coating of some protective material or vitreous enamel such as porcelain to provide a pleasing and sanitary appearance in accordance'with the usual practice. The outer sheet metal covering IS on the back of the cabinet extends completely to the top and the outer top covering extends entirely to the .back thereby providing. an enclosed ma chine compartment l'l on the machine shelf H. The food storage compartment l8 enclosed by the cabinet 'is provided with shelves. I 9 which rest upon suitable supports 2| projecting from the side Walls 9.

To cool the food storage compartment a cooling plate 23 is mounted in the upper portion of the compartment on the vertical wall l3 adjacent the machine compartment. The cooling plate 23 is a refrigerant evaporator for receiving volatile liquefied refrigerant which is vaporized by the heat in the food storage compartment. The evaporator may comprise either a flat plate to which serpentine coils of a continuous conduit are secured in intimate thermal relation as by welding or soldering, or it may be a flat elongated chamber, either construction having inlet and outlet'conduits 25 and 21 connected thereto. In either construction it is desirable to increase the thermal coupling of the cooling plate 23 with the atmosphere in the food storage compartment which may be accomplished by providing a plurality of heat conductive fins 29 in intimate thermal relation thereon as by welding or soldering a plurality of channel shaped metallic strips thereto in adjacent parallel relation.

To provide a low temperature freezing chamber for quick freezing ice cubes, desserts, and the like, a partition enclosure member 3| is secured to the central portion of the cooling plate 23, and freezing plates 33 are mounted between the side walls thereof and comprise shelves fortrays 35 supporting the material to be frozen. The freezing plate shelves .33 in the partition enclosure 3| may each comprise a fiat, elongated chamber, or a plate to which coils of refrigerant conduit have been welded or soldered. The freezing chamber W Although only two freezing plates 33 are shown in the freezing chamber it will be understood that as many plates may be provided as desired. Suitable interconnecting conduit means 31 carries the refrigerant through the freezing plates33 in series relation, and the outlet conduit 21 from the cooling plate 23 extends through a weighted pressure reducing valve 39 to the first one of the series of freezing plates.

A suitable refrigerant condensing unit 4| mounted in the machine compartment I'I continuously withdraws refrigerant vapor from the freezing plates 33, condenses it, and returns the liquefied refrigerant to the finned cooling plate 23. Such a condensing unit may comprise a compressor pump driven by a suitable electric motor hermetically enclosed together therewith in a suitable casing 4|, and connected to draw the re-' frigerant vapor from the freezing plates 33 through a suction line 43 which is connected thereto. From the compressor 4| the vapor passes under high pressure through a conduit 45 into a finned condenser 41 where its latent heat of vaporization is dissipated to the surrounding atmosphere, and the vapor is condensed to a liquid. To increase the heat dispersing capacity of the condenser 41 an adjacent fan 49 may be provided to circulate air therethrough. From the condenser 41 the liquefied refrigerant passes through a conduit to the cooling plate 23. A liquid receiving vessel such as a high side float chamber 53 may be interposed between the compressor and the cooling plate to regulate the flow of liquefied refrigerant thereto. The suction line 43 and the liquid refrigerant conduit 5| extend through the vertical heat insulating wall |3 between the food storage compartment and the compressor machine. The cooling plate 23 is rigidly secured to the vertical wall l3 and with the compressor unit may be inserted from the open front doorway for convenient assembly in substantially the same manner as is described and disclosed in my Patent No. 2,065,536 for Refrigerating apparatus.

The compressor unit 4| is preferably automatically controlled to operate intermittently in accordance with the temperatures in the food storage compartment by means of a conventional thermostatic switch in accordance with the usual practice. To admit cooling air to the finned condenser 41 the rear of the machine compartment I1 is left open to the surrounding air.

I In operation the compressor withdraws the vaporized refrigerant through the suction line 43 compresses it and passes it under high pressure into the finned heat dissipating condenser 41 where its latent heat of vaporization is transferred to the surrounding atmosphere and the refrigerant vapor condenses to aliquid. The

- liquefied refrigerantthen passes into the finned perature than is the refrigerant in the freezing plates 33 which are connected directly to the suction side of the compressor through the suction-line 43. The weighted valve is selected to provide a suitable range of temperatures in the finned cooling plates such that it will automatically defrost during the off periods of the compressor and will then melt the ice and frost which formed on the fins during the on period. The transversely mounted cooling plate 23 and its parallel fins exposes a large thermal conduc tive surface which serves to rapidly absorb the heat from the air in the food storage compartment as it circulates therethrough and quickly cools the storage compartment to the desired temperature during the on period of the compressor.

I have provided another embodiment of my cooling unit which is especially suit-able for mounting in a refrigerator cabinet when the heat insulating top wall 6| of the food storage compartment extends entirely across the top of the cabinet and a machine compartment 63 is provided on top of the cabinet, as shown in Fig. 4.

- In this embodiment the heat insulating top wall 6| of the storage compartment serves as the base for mounting the compressor unit 4| and its accessories, and it is provided with bevelled or inclined edge surfaces 65 to seat in tightly wedged relation upon inclined surfaces cooperatively disposed around the top of the cabinet. A rubber gasket 61 may be interposed between the engaging surfaces to make a sealed joint.

The finned cooling plate 23 is mounted horizontally on the lower surface of the top wall 6| and it extends transversely across the cabinet. The enclosure 3| which provides the freezing chamber, is suspended below the cooling plate with its hinged door 34' adjacent the doorway of the refrigerator. The freezing plates 33 which comprise the shelves in the freezing chamber are interconnected in series relation by suitable condrawn from the last one of the series of freezing plates-are both extended through the removable heatinsulating top wall 6|. which comprises the machine base. By this arrangement the cooling plate, the freezing chamber enclosure, the compressor unit, and accessories may all be very conveniently removed, as a unit by lifting the structure upwardly from the cabinet. A substitute unit may then be readily-inserted in the cabinet while the original unit is returned for servicing. This is a very useful arrangement'as it enables the skilled serviceman to remain at the service station and all his time is usefully applied to servicing the apparatus instead of driving about from place to place to pick up the units which can be attended to by less skilled labor. This is also a great advantage when making the original installation in the cabinet since the compressor may be connected to the cooling plate, freezing plates, and accessories and the adjustments may be made at the factory.

The unit may then be shipped separately to a dealer or other point of assembly where the unit may be quickly and conveniently installed by dealers assistants or other unskilled persons.

In operation the weighted pressure reducing valve 39 between the cooling plate and the freezing plates is so adjusted or selected that a suitable temperature differential is maintained therebetween and the variation of the cooling plate temperatures during the intermittent operation of the compressor unit causes the ice and frost to melt 0d of the fins on the cooling plate whereby it is automatically defrosted whilst the freezing temperatures are maintained within the freezing chamber.

It will be seen that I have provided a cooling unit comprising two different temperature zones one of which is automatically defrosting and which may be conveniently mounted, as a unit in an effective position in a refrigerator cabinet.

I claim as my invention:

1. In combination in a refrigerator, heat insulating walls enclosing a food storage compartment, an adjacent machine compartment, a refrigerant compressor unit in the machine compartment, a vertically disposed finned cooling plate extending across the upper portion of said food storage compartment, a freezing chamber enclosure projecting horizontally from said cooling plate into said food storage compartment, and freezing plates in said freezing chamber.

2. A cooling unit for use-'in refrigerators comprising a substantially flat plate evaporator, metallic fins on one surface of said plate evaporator, a freezing chamber secured to an intermediate portion of said plate evaporator on the same side as said fins, freezing plates comprising shelves in said chamber, conduit means operatively interconnecting said plate evaporator and said freezing plates in series relation, pressure reducing means interposed in said conduit means between said plate evaporator and said freezing plates and a door closing said freezing chamber.

LAWRENCE A. PED'JPP. 

